Originally posted by warmonger:
I swapped the GReddy device out and I will wait to see whether they will warranty it or try to charge me to fix it. I won't pay them a dime however since I found the chip that burnt at www.digikey.com for $0.69 each. I ordered four of them.
Here is what happened: The chip in question has 7 transistor gates on it, six of which are meant to fire the ignition coils. The problem is that they are only capable of sinking 500 miliamps of current. Our coils on our engine are less than 5 ohms resistance, so they allow close to 10 amps!
That was why the chip toasted immediately.
Steve and I have put our collective brains together and come up with a simple and cheap solution that will enable us to use the GReddy to fire the ignition coils without burning anything up. We will use 3 high-current mosfets that will be activated by the GReddy unit and in turn will fire the coils. This will allow the full use of the ignition timing map and still protect the GReddy unit from destruction.
I will schedule dyno time for next Thursday with Streetflight in Chandler AZ. This is the place making the Turbo kit. That is where I dyno'd my car last time, so I should be able to see just what kind of gains the GReddy can make for us.
warmongerDigikey is the shizz - if you can't find it there then it doesn't exist! Only problem with them is that they might make you make a minimum purchase. Although I doubt you'll find any problem finding $25 worth of stuff in there.
The MosFETs are the way to go - that's exactly what is in the PCM for ignition firing. (I could tell a really long story about bum FETs in the PCM causing a few plants to build cars w/o PCMs until we could get them good ones.) If you are feeling especially adventurous, you could pull the cover off the PCM to find out exactly what is used, although it migh have a Ford P/N silkscreened on it instead of a manufacturer's part number. It's been a long time since I worked at good old Ford so I forget. Make sure you get some good heatsinks for them or you'll pop them like popcorn (but I bet you already know that).
Better horsepower through electronics! Gotta love it.
